1. Technical Field
The present invention relates to a liquid container for containing liquid used in a liquid consuming apparatus.
2. Related Art
In a liquid consuming apparatus that consumes liquid, a technology for managing a liquid consumption amount is known. As a liquid consuming apparatus, for example, a printing apparatus which has one or a plurality of ink cartridges mounted therein and performs a printing process using ink is known. As a technology for managing an ink residual amount, a technology for determining whether the amount of ink contained in an ink cartridge is equal to or less than a predetermined ink amount using a piezoelectric sensor is known.
In the technology using the piezoelectric sensor, it is determined whether the amount of ink contained in the ink cartridge is equal to or less than a predetermined ink amount, on the basis of a difference between a frequency (Empty frequency) of a detection signal output from the piezoelectric sensor when the amount of ink contained in the ink cartridge is equal to or less than the predetermined amount and on the basis of a frequency (Full frequency) of a detection signal output from the piezoelectric sensor when the amount of ink contained in the ink cartridge is greater than the predetermined amount (see, for example, JP-A-2003-39707).
However, in the technology using the piezoelectric sensor, since a difference between a natural frequency of a vibration system in a case where ink is not contained in the vibration system and a natural frequency of a vibration system in a case where ink is contained in the vibration system is used, both natural frequencies are different from each other. Accordingly, since one natural resonance frequency (resonance frequency) cannot be detected in a driving signal having the other natural frequency, the driving signal having an Empty frequency and the detection signal having a Full frequency need to be used for detecting the detection signal having the Empty frequency and the detection signal having the Full frequency.
The detection signal may be detected with respect to only any one of the case where the ink is not contained in the vibration system and the case where the ink is contained in the vibration system such that it is determined whether the amount of ink contained in the ink cartridge is equal to or less than the predetermined amount. However, in this case, determination precision is low. For example, due to noise, when the detection signal having the Full frequency is used, the detection signal having the Full frequency may be obtained although the amount of ink contained in the ink cartridge is equal to or less than the predetermined amount. In this case, idle driving is performed and thus a print head may be damaged.